A. Field of Invention
The present invention relates to a laser system having an optical fiber. The laser system energizes Yb3+ in a multiclad optical fiber core that is essentially devoid of Nd3+ to produce an optical gain. The optical fiber can be glass, crystalline, or a combination thereof, and made out of a halide or chalcogenide host or combinations thereof. The optical fiber can be energized by direct pumping of by indirect pumping. The optical fiber can be incorporated into an amplifier, an oscillator, or a superluminescence source. The output can be applied to communications, a gyroscope or other sensors, printing, and medical instruments.
B. Description of the Related Art
There is a need to amplify optical signals in many fields of technology. In fiber optic communications, for example, to send cable television signals to many households over optical fibers, it is necessary to split the signals into many receivers. Without amplification, one would in all practicality eventually run out of signal to divide. It is through amplification (increasing the strength of the signal) that such signals can be provided to many households. One way to amplify the light signals is to convert then to electrical signals, amplify the electrical signals, and than reconvert the electrical signals back to light again. This is a relatively complicated and expensive approach, but it is necessary where there is no known, practical device that can optically amplify the relevant region of the light spectrum.
For example, prior to this invention, it has been essentially necessary to use electrical rather than optical amplification for one of the primary wavelengths used in communications. Further, in the search to find a way to optically amplify certain wavelength regions, despite great efforts, solutions have been elusive.
It is an object of the present invention to provide an optical fiber core doped with Yb3+ in an amount sufficient to produce a gain in a multiclad core essentially devoid of Nd3+.
It is a further object of the present invention to provide methods of making the optical fiber.
It is another object of the present invention to provide methods of making the optical fiber using hosts that are glass, crystalline, or a combination thereof.
It is another object of the present invention to provide methods of making the optical fiber using a fluoride or other halide host, or using a chalcogenide host, or a chalco-halide host.
It is another object of the present invention to improve the optical fiber with at least one co-doped sensitizer.
It is another object of the present invention to provide methods for using the optical fiber in an oscillator and in an amplifier.
These and other objects that will be apparent from the following disclosure are accomplished by energizing a multiclad core of an optical fiber doped with Yb3+ to produce ions energized to produce an optical gain. The optical fiber can have one or more sensitizers co-doped with the Yb3+, but the core is essentially devoid of neodymium (Nd3+). The optical fiber can be incorporated into an amplifier or an oscillator to provide light for communications, a gyroscope or other sensors, printing, and medical applications.